Heavy duty nibbler

ABSTRACT

A heavy duty nibbler possessing certain improvements over the nibbler tools of U. S. Pat. Nos. 2,888,744, 2,967,355 and others, including a punch that is threadedly seated in a main body part such that it is not necessary to remove any parts when the punch is threadedly withdrawn from the bottom of the main body part. The punch is of half-moon shape so that the punch makes an initial partial cut into the work. The portions of the punch are angularly related such that the punch is divided into an extending leg having a flattened edge and a main stem with an inclined edge, the angle between the flattened edge and the inclined edge lying between 81* and 83*. The heavy duty nibbler tool further includes a bronze guide sleeve that replaces the nosepiece of U. S. Pat. Nos. 2,888,774 and 2,967,355. The bronze guide sleeve will guide the plunger or ram, thereby preventing the punch from running off center. In the present invention the die is provided with ripples to prevent the metal from backing out, and the die holder is provided with a concave surface. Furthermore, the stripper mechanism is adjustable through the addition of stripper plates in 1/16 increments. Thus, the stripper can be adapted for different thicknesses of the work by simply inserting one or more plates in the top of the stripper. Finally, the main driven gear is provided with a series of openings to eliminate backlash.

i Waited States Patent 8 1 Yermis [5 1 HEAVY DUTY NIBBLER [75] Inventor:Israel J. Yermis, Philadelphia, Pa.

[73] Assignee: Fenway Machine Co., Philadelphia,

[22] Filed: June 27,1972

21 Appl.No.:266,805

52 us. (:1. 30/241 [5i] Int. Cl B26b 15/00 [58] Field of Search 30/228,241, 242, 30/243; 83/395 [56] References Cited UNITED STATES PATENTS2,696,044 12 1954 Dod egge 30/241 2,329,387 9/1943 Brenning... 30/242 X2,650,663 9/l953 Wales 83/395 2,567,095 9/l95l Benjamin 30/24] X2,827,696 3/l958 Yermish 30/228 2,680,292 6/1954 Kaufmann 30/228 PrimaryExaminerDonald G. Kelly Assistant Examiner-J. C. Peters Attorney-Caesar,Rivise, Bernstein and Cohen [5 7] ABSTRACT A heavy duty nibblerpossessing certain improvements over the nibbler tools of U. S. Pat.Nos. 2,888,744,

[ Jan. 15, 1974 2,967,355 and others, including a punch that isthreadedly seated in a main body part such that it is not necessary toremove any parts when the punch is threadedly withdrawn from the bottomof the main body part. The punch is of half-moon shape so that the punchmakes an initial partial cut into the work. The portions of the punchare angularly related such that the punch is divided into an extendingleg having a flattened edge and a main stem with an inclined edge, theangle between the flattened edge and the inclined edge lying between 81and 83.

The heavy duty nibbler tool further includes a bronze guide sleeve thatreplaces the nosepiece of U. S. Pat. Nos. 2,888,774 and 2,967,355. Thebronze guide sleeve will guide the plunger or ram, thereby preventingthe punch from running off center.

In the present invention the die is provided with ripples to prevent themetal from backing out, and the die holder is provided with a concavesurface.

Finally, the main driven gear is provided with a series of openings toeliminate backlash.

10 Claims, 5 Drawing Figures magnum 15 um 3.785.052

SHEET 10? 3 PA'IENTEDJAM 15 am SHEEF 30? 3 tool and more particularly toa new and improved de-- vice of this general class. The presentinvention constitutes an improvement over U.S. Pat. Nos. 2,888,744,

2,967,355 and others.

Nibbler tools have been gradually improved during the last twenty yearsas exemplified by U.S. Pat. Nos.

2,827,696, 2,844,872, 2,888,744 and 2,967,355.

- The devices of theforegoing patents have generally involved means toreciprocate a punchholding ram, the ram possessing a central opening toreceive apunch shank, a die plate carried by a guide and a stripper.Heretofore, the punch was dropped into the bore of the ram and then heldin place by threaded bushings, as

shown in U.S. Pat. No. 2,967,355. This not only made the seating of thepunch a somewhat intricate operation. but greatly complicated theremoval and replacement of the punch.

Furthermore, the nosepiece of the prior devices was relatively expensiveto manufacture, but was necessary to the proper operation of the nibblertool.

Such prior devices were equipped with dies which, sometimes, allowed themetal to back out, and the die holders of such devices possessed agenerally straight edge as distinguished from the concave surface of thepresent invention.

The stripper mechanism in such devices was not adjustable and so wasforced to act on varying thicknesses of the work. Finally, the geartrain of the prior devices was comprised of a solid main gear and thisled to backlash.

It is a principal object of the present invention to overcome theshortcomings of the prior art by providing a heavy duty nibbler whichcomprises a threadedly adjustable punch that is inserted upwardly into athreaded opening in the main body part.

Yet another object of the present invention is to eliminate thenosepiece of the prior devices and to instead provide a bronze guidesleeve for guidance of the ram or plunger to prevent the punch fromrunning off center.

Still another object of the present invention is to provide a heavy dutynibbler tool of reasonable cost which can cut faster than prior toolsand act upon thicker work pieces.

Still another object of the present invention is to provide a die withripples to keep the work from backing out and to provide a die holderwith a concave surface.

Yet another object of the present invention is to provide a heavy dutynibbler tool with a stripper mechanism that is adjustable to accommodatevarying thicknesses of work and which possesses a main gear havingopenings to prevent backlash.

Other objects and many of the attendant advantages of the invention willbe more readily understood by ref-,

erence to the following figures of the drawings wherein:

FIG. 1 is a side elevational view of the heavy duty nibbler of thepresent invention with certain outer portions removed in order to showvarious operative elements of the present invention;

FIG. 2 is an enlarged sectional view taking along the lines 2-2 of FIG.1;

FIG. 3 is an enlarged sectional view taken along the lines 3--3 of FIG.1;

'FIG. 4 is.a three-dimensional exploded view showing the plunger or ramand a punch about to be threadedly engaged in thebore of the plunger orram; and

FIG. 5 is a three-dimensionalexploded view showing the strippermechanism, a stripper plate for adjustment purposes, the die and the dieholder.

Referring now in greater detail to the various figures of the drawingwherein like reference characters refer to like parts, there isgenerally shown at 10 in FIG. 1 a heavy duty nibbler constituting anembodiment of the present-invention.

The heavy duty nibbler 10 is provided with a body 11, a head l2 that ismounted upon the body 11 in axial extension t hereof with the nose ofthe prior devices having been eliminated and replaced with a bronzeguide sleeve 13 (FIG. 1).

The body 11 houses an electric motor (not shown) that is supplied withpower through the medium of a cable 14, the electric motor beingcontrolled by the operator through finger pressure applied to a switchcontrol lever 15 that is mounted upon a handle 16. Note also head handle16A (FIG. 1).

The body 11 and the head 12 are internally provided with means,presently to be described, for translating the rotary motion of theelectric motor into reciprocating motion of a punch generally designated18 (FIGS. 1 and 4), the latter being operatively mounted in a punchholder 20 that is actuated in a down and upstroke by ram 22.

The means for translating rotary motion of the electric motor intoreciprocating motion of the punch 18 comprises a generally cylindricalplunger or ram 22 that is provided with a main body part or stem (FIG.2). Extending transversely through the main body part of the ram 22(FIG. 2) is a rectangular opening 24 that is defined by horizontallyextending upper and lower walls designated respectively 26 and 28 andvertically extending opposite end walls designated respectively 30 and32. As can be seen in FIG. 4, the punch holder 20 may be an integralpart of the ram 22.

As can be best seen in FIG. 4, the punch 18 is of halfmoon shape so thatit is effectively divided into extending leg 34 with flattened edge 36and main stem 38 with inclined edge 40. As can be seen in FIG. 1, theflattened edge 36 is essentially a straight cut whereas the inclinededge 40 is not quite perpendicular to the flattened edge 36. Thepreferred angle between the flattened edge 36 and the inclined edge 40lies between 81 and 83. If the angle drops to about then inclined edge40 points too directly into the work and achieves too much of a bite. Onthe other hand, if the angle between the flattened edge 36 and theinclined edge 40 opens up to 84 or more, there is an undesirable pushingaction.

It can also be seen from FIG. 4 that the punch holder 20 has a centralthreaded bore 42 as well as a threaded side opening 44 for reception ofset screw 46. Also seen in FIG. 4 is access opening 48 in upper wall 26of ram 22.

From the foregoing it can be seen that the punch 18 is simply threadedinto place with the threads 18-A formed on the upper shank of the punch18 being received in the central threaded bore 42. Once the punch hasbeen threadedly inserted to the approximate desired depth, it is asimple matter to insert a tool through access opening 48 in order tograsp the upper edge of the punch 18 and rotate it to a desired level.Then, a

set screw 50 (which-had been preinserted) can be tightened as well asside set screw 46 through access opening 52 (FIG. 1).

It will be seen that the bronze guide sleeve 13 completely replaces thenosepiece of the prior devices. The bronze guide sleeve 13 guides theram 22 in its downward and upward stroke and prevents the punch 18 fromrunning off center.

The means for translating rotary motion of the electric motor intoreciprocating motion of the punch 18 additionally comprises a pair ofball bearing units designated 56-56 respectively mounted in thetransversely extending casing walls 58 and 60 (FIG. 1). Journalled inthese units are concentric opposite end portions, respectivelydesignated 62 and 63, of a shaft that is projected through the ram 22. I

The intermediate portion of shaft 64 (with concentric opposite endportions 62 and 63) is eccentrically disposed relative to the oppositeend shaft portions 58 and 60 and is revolvably extended through acentral aperture 66 (FIG. 2) formed in a slide block 68 which is mountedin the ram 22 for shifting movement from side to side within therectangular opening 24. The shaft portion 63 is operatively connectedwith the electric motor through the medium of a gear train designatedgenerally by the numeral 70 (FIG. 1).

In the operation of the tool, the eccentric shaft rotates in theconcentric bearing units 56-56, about its principal axis and theintermediate eccentric shaft portion 64 rotates therewith forreciprocating as a unit the assembly, including the slide block 68, ram22 and punch 18. It will be observed that the eccentric shaft isadequately supported at both ends thereof in the bearing units 56-56mounted respectively in the casing walls 58 and 60 on opposite sides ofram 22.

As can be seen in FIG. I, the main shaft 72 from the electric motor (notshown) meshes with a gear 74 which in turn 'meshes with a larger gear 76of the gear train 70. Concentric end 63 of the shaft 64 is in turnrotated by the larger gear 76. This relationship is shown in more detailin FIG. 3 wherein the concentric shaft 78 of the smaller gear 74 isactually a spur gear that meshes with the larger gear 76 which possessesgear teeth 80.

It is to be noted that the larger gear 76 is fitted with five transverseholes 82 for the purpose of eliminating backlash or kick.

Attention is now called to FIG. which shows the stripper mechanism 90 aswell as die holder 92 positioned below the stripper mechanism 90 asshown in FIG. 1.

The stripper mechanism 90 possesses a body 96 and there is a connectingweb 98 that connects the stripper mechanism 90 and the die holder 92.There are four bolt holes 100 in the body 96 that allow the passage ofbolts for attachment to the head l2.

Also formed in the stripper mechanism 90 is a hole 102 that allows thepassage of punch 18 on its downward and upward strokes. With furtherreference to FIG. 5, it will be seen that a lug 104 is provided havinglegs 106 that extend upwardly as well as an arcuate edge 108 formedadjacent one end of the lug 104. There is additionally an arcuate spacebetween the legs 106.

From FIG. 5 it can be seen that the lug 104 is received against thestripper mechanism 90 with the legs I06 extending into an appropriateslot in the stripper mechanism 90 and held in place by the clampingaction of end plate 1 18 and bolt 120 that passes into the arcuate space110 that is then received in an appropriate opening in the strippermechanism 90.

The stripper mechanism may be rendered adjustable to accommodatedifferent thicknesses of metal with the provision of one or morestripper plates 112 that are basically of a rectangular shape but have aslot 114 and an arcuate edge 116 that generally coincides with thearcuate edge 108 of the lug 104. One or more stripper plates may beinterposed between the lug 104 and the stripper mechanism 90 therebyenabling the stripper mechanism 90 to handle work of differentthickness, with more plates used with thinner workpieces.

The die holder 92 possesses openings 122 to receive bolts (not shown) tosecure the die holder 92 to the punch guide 54.

The die holder 92 further includes a slot 124 for receiving the punch 18on its downward stroke. A recessed surface 126 is provided for receiptof the die plate 128 which possesses ripples 130 to keep metal removedfrom the work from backing out. The die plate 128 also includes a slot132 that coincides with slot I24 to allow passage of the punch 18 on itsdownward stroke. Finally, a front plate 134 is provided and secured byappropriate bolts.

It is therefore seen that the present invention provides a highlysatisfactory heavy duty nibbler. The reciprocal plunger or ram possessesa punch holder with a threaded bore to receive a punch of novelconstruction by direct threading. The reciprocal mechanism for drivingthe punch includes a main gear with a series of openings to eliminatebacklash. Also, a bronze guide sleeve is provided so that the heavy dutynibbler does not depend upon a nosepiece for its operation.

Furthermore, the heavy duty nibbler of the present invention includes anadjustable stripper mechanism as well as a die with ripples to keep themetal from backing out.

Without further elaboration, the foregoing will so fully illustrate myinvention that others may, by applying current or future knowledge,readily adapt the same for use under various conditions of service.

What is claimed as the invention is:

l. A heavy duty nibbler comprising reciprocating means, an elongatedpunch having a working end and a threaded shank spaced from the workingend, a plunger driven by said reciprocating means and including a punchholder for holding the punch and possessing a threaded bore and anaccess opening, with the threaded shank of the punch being received insaid threaded bore, said access opening providing access to the bore topermit a tool to be inserted therein to expedite the connection ordisconnection of the punch from the punch holder.

2. The heavy duty nibbler of claim 1 wherein said reciprocating meansinclude a main gear having openings to eliminate backlash.

-3. The heavy duty nibbler of claim 1 wherein said punch is of half-moonshape at said working end.

4. The heavy duty nibbler of claim 3 wherein said half-moon shape iseffectively divided into an extending leg with a flattened edge and amain stem with an inclined edge.

5. The heavy duty nibbler of claim 4 wherein the flattened edge and theinclined edge are related to each other in an angle varying between 81and 83.

least'one stripper plate that is secured to said stripper mechanism foradjustability purposes.

9. The heavy duty nibbler of claim 1 wherein said access opening isaxially aligned with said bore and wherein a set screw is disposedwithin said threaded bore.

10. The heavy duty nibbler of claim 9 wherein a side set screw isprovided in the punch holder to aid in the securement of the punchtherein.

1. A heavy duty nibbler comprising reciprocating means, an elongatedpunch having a working end and a threaded shank spaced from the workingend, a plunger driven by said reciprocating means and including a punchholder for holding the punch and possessing a threaded bore and anaccess opening, with the threaded shank of the punch being received insaid threaded bore, said access opening providing access to the bore topermit a tool to be inserted therein to expedite the connection ordisconnection of the punch from the punch holder.
 2. The heavy dutynibbler of claim 1 wherein said reciprocating means include a main gearhaving openings to eliminate backlash.
 3. The heavy duty nibbler ofclaim 1 wherein said punch is of half-moon shape at said working end. 4.The heavy duty nibbler of claim 3 wherein said half-moon shape iseffectively divided into an extending leg with a flattened edge and amain stem with an inclined edge.
 5. The heavy duty nibbler of claim 4wherein the flattened edge and the inclined edge are related to eachother in an angle varying between 81* and 83*.
 6. The heavy duty nibblerof claim 1 including a bronze guide sleeve that is positioned about saidpunch holder.
 7. The heavy duty nibbler of claim 1 including a die withwhich said punch acts, said die having ripples to keep metal removedfrom the workpiece from backing out.
 8. The heavy duty nibbler of claim1 including an adjustable stripper mechanism operating in conjunctionwith said punch, said stripper mechanism including at least one stripperplate that is secured to said stripper mechanism for adjustabilitypurposes.
 9. The heavy duty nibbler of claim 1 wherein said accessopening is axially aligned with said bore and wherein a set screw isdisposed within said threaded bore.
 10. The heavy duty nibbler of claim9 wherein a side set screw is provided in the punch holder to aid in thesecurement of the punch therein.